This invention relates to a photostimulator to be used for electrophysiological examinations, and particularly for the measurements of evoked visual potentials, suited to cooperation with automatic systems for analysis of electrophysiological signals, the said photostimulator consisting of a stimulation source of a biological object and a control unit for the control of the said source.
Those skilled in art know the following designs of photostimulators producing light stimuli (collective work edited by John E. Desmedt entitled "Visual evoked potentials in man: new developments"--Clarendom Press--Oxford--1977--page 3--15). Electronic photostimulators with spark lamps with pulse-like operation do not provide any possibility of application of a function understood as a variability of a light flux of an individual glowing element (all glowing elements emit the same flux in the form of arbitrary variations e.g. sinudoidal, trapezoid etc. with a constant component of the light flux or without it), the shape being understood as a steady configuration of glowing elements on a luminescence matrix for a given time interval (only some of the glowing elements on the luminescence matrix are simultaneously glowing, said glowing elements forming e.g. horizontal or vertical stripes, grates, bents, circles, letters or the like, or, finally, the chosen fields such as e.g.: horizontal or vertical halves, quarters etc.), the shape being dependent upon the reflection screen being used on which black and white fields are painted (check or the so called checkered pattern), imitating the glowing elements at the time of illumination of the screen by the spark lamp. Electronic photostimulators with spark lamps also do not afford any possibility of varying the form understood as a continuous or step-like displacement of the shape on a luminescence matrix (reversibility of the neighbouring glowing elements, or the whole patterns, that is stripes, hemispheres, quarters, as well as circulation of the stripes or quarters around a central point). Electronic photostimulators with a TV kinescope are known on which an arbitrary shape can be obtained, but with the limited possibilities of reproduction of a function or form because of the extinguishing time (after-glow duration) of a kinescope screen. Optical photostimulators with mechanical projecting systems and film screens, where the required function, shape and form can be obtained by means of the respective motion of diaphragms and mirrors are known, but with considerable time limitations of the said function, shape and form depending upon inertia of the mechanical systems (diaphragms and mirrors). Those skilled in art also know the photostimulator described in the Polish patent specification No. 73,416, which may be put in a group of electronic photostimulators with a spark lamp and with pulse-like operation. This invention the design of such a photostimulator which would render possible widening of the range of possible examinations of eyesight in connection with cortex reactions (evoked visual potentials) to light stimuli.